General topicsstatus: review status: review
Resilience refers to the performance and evolution of energy systems under disruptions, from acute shocks like extreme weather and cyberattacks to chronic stresses like shifting demand patterns and climate change. Thinking about resilience goes beyond absorbing shocks to include how systems adapt to the changing nature of disruptions and how they transform to safeguard essential functions over the long term.
Electricity systems were designed around a narrower range of threats than they now face. Extreme weather events are increasing in frequency and severity, cyber threats target both operational technology and data infrastructure, and chronic stresses from ageing assets and shifting generation mixes compound over time.
An acute example is the April 2025 Iberian blackout that collapsed the entire Spanish-Portuguese system within seconds. Technically mature renewable installations were operating without grid-forming inverter capabilities, and coordination protocols between TSOs had not been designed for a system where renewables supplied 78% of generation. Technical readiness in individual components did not translate into system-level resilience.1)
The number of actors involved in system operation is growing, and the coordination required to manage disruptions cuts across technical, regulatory, and governance domains.
Smart grid transitions redistribute where resilience sits in the system. Distributed generation and storage shift some resilience functions from central infrastructure to the grid edge, where households, communities, and microgrid operators become participants rather than passive consumers. Meanwhile, digitalisation makes new forms of coordination possible but also introduces cyber vulnerabilities that did not exist in analogue systems. Whether these changes strengthen or weaken overall resilience depends on how well technical design, institutional rules, and the capacities of different actor groups are aligned with each other.
Resilience in energy systems encompasses the capacity to anticipate, withstand, respond to, and recover from disruptions while developing and transforming over time to maintain core functions. Two dimensions structure the concept. The first concerns disruptions: the SINTEF/NTNU risk pyramid arranges these along a severity gradient from everyday operational events through serious incidents to catastrophic system failures, each requiring distinct governance and response types. The second concerns the capacities a system can draw on.
| Capacity | What it involves | Smart grid examples |
|---|---|---|
| Absorptive | Withstanding shocks without loss of core function through redundancy, robustness, and rapid response | Redundant communication paths, fault-tolerant grid design, ruggedised critical components |
| Adaptive | Adjusting system configuration and operation in response to changing conditions, maintaining function through flexibility | Demand response programmes, flexible grid topologies, updated operating procedures, decentralised generation |
| Transformative | Reconfiguring system architecture when existing arrangements cannot absorb or adapt to the scale of disturbance | Restructuring grid infrastructure and regulatory frameworks, transitioning from centralised to distributed architectures |
| Anticipatory | Identifying future risks and preparing responses before disruptions materialise | Climate impact modelling, scenario-based grid planning, horizon scanning, blackout preparedness exercises |
These capacities interact. Anticipation informs investment in absorption and adaptation, while timely adaptation may ease the deeper reconfigurations that transformation requires. A resilient system draws on all four, weighted according to the threats it faces and the time horizon it plans for.
How resilience plays out in practice depends on who is responsible for it, what technical capabilities are in place, and which rules govern how actors respond. The three perspectives below examine resilience from each of these angles. Where they overlap, particularly around data infrastructure and coordination protocols, the interactions matter as much as the individual dimensions.
System operators carry primary responsibility for operational resilience, but as grids become more decentralised, the contributions of households with battery storage, energy communities, and microgrid operators gain significance. Different actors hold different views on resilience depending on how they use electricity, which constraints affect them most, and what timescales matter for their decisions. A transmission system operator planning infrastructure investments over decades faces different resilience questions than a community microgrid operator managing seasonal cyclone risk. Coordination among these groups, through knowledge exchange, resource sharing, and rapid response protocols, shapes whether resilience benefits are distributed equitably.
Japan — post-Fukushima resilience restructuring
The systemic response to the 2011 disaster involved multiple actor groups: utilities restructured generation portfolios, regulators overhauled safety and market rules, municipalities developed local energy resilience plans, and households adjusted consumption patterns. The 7th Strategic Energy Plan, adopted in February 2025, continues to place energy security alongside decarbonisation as a core policy pillar.2)
Puerto Rico — post-hurricane grid reconstruction
Rebuilding the electricity system after Hurricanes Irma and Maria in 2017 involved federal agencies, the utility PREPA, municipal governments, and community organisations, exposing how fragmented institutional responsibilities can slow resilient recovery.3)
Bangladesh — cyclone-resilient energy infrastructure
Communities in coastal areas have worked with NGOs and government agencies to develop resilient off-grid solutions that withstand frequent cyclone exposure, demonstrating that resilience building in resource-constrained settings depends on local actor capacity as much as technology.4)
System architecture, how technical components are arranged and how they interact, is a major factor in a grid's resilience. Wide-area monitoring provides situational awareness during disturbances. Advanced distribution management systems enable rapid reconfiguration after faults. Microgrids with islanding capability allow critical facilities to maintain power during wider outages. Redundancy in communication networks ensures that monitoring and control functions survive localised failures. What distinguishes resilient architecture from robust architecture is the capacity not only to withstand shocks but to reconfigure in response to them.
Australia — South Australia system resilience programme
Following the September 2016 statewide blackout, the South Australian government and AEMO implemented a coordinated response including the Hornsdale Power Reserve, updated frequency control requirements, and revised grid connection standards for wind and solar that addressed the specific technical gaps the event had exposed.5)
Spain and Portugal — April 2025 Iberian blackout
The loss of approximately 15 GW of generation within five seconds revealed how inverter-based renewable plants operating in fixed-power-factor mode contributed to cascading failure. The ENTSO-E factual report identified excessive voltage as the probable trigger, with plants disconnecting automatically to protect equipment rather than actively supporting the grid.6)
Denmark — Bornholm island microgrid demonstration
The EcoGrid EU project tested whether a distribution network with high wind penetration could operate in islanded mode, providing evidence on technical resilience capabilities for isolated systems dependent on variable generation.7)
Regulatory frameworks shape how resilience is defined, measured, and invested in. Performance-based regulation can reward utilities for improving resilience outcomes rather than simply expanding infrastructure. Market designs that value fast frequency response, black start capability, and voltage support create commercial pathways for resilience provision. Cross-sector planning for interdependencies between electricity, telecommunications, water, and transport helps ensure that resilience in one domain does not depend on fragile assumptions about another.
United Kingdom — Ofgem resilience obligations
The RIIO-ED2 regulatory framework includes specific output targets for network resilience, including flood protection and overhead line undergrounding in high-risk areas, linking operator revenue directly to measurable resilience performance.8)
Nigeria — grid resilience governance
The institutional separation of generation, transmission, and distribution across different entities creates coordination challenges, particularly at the interface between the Transmission Company of Nigeria and regional distribution companies where operational responsibilities overlap.
Chile — critical infrastructure protection framework
Institutional arrangements for protecting electricity infrastructure against seismic and climate-related hazards reflect the country's geophysical realities, illustrating how regulatory design can embed resilience requirements that are specific to local conditions rather than imported from generic templates.
| Term | Definition |
|---|---|
| Black start capability | The ability of a power system or generation unit to restart without relying on external electricity supply, a key operational function following a complete system blackout.9) |
| Preparedness | The ability to anticipate risks, plan strategically, and coordinate effective responses across governance levels before disruptions occur. Complementary to resilience, with emphasis on foresight and institutional coordination rather than system performance during and after an event.10) |
| Grid-forming inverter | An inverter that establishes its own voltage and frequency reference, enabling it to support grid stability independently rather than synchronising to an existing grid signal. Systems with high shares of inverter-based generation require grid-forming capability for voltage control and black start.11) |
| Islanding | The ability of a portion of the distribution network or a microgrid to disconnect from the main grid and operate independently during a wider system disruption, maintaining local supply to critical loads.12) |
| Defence plan | A coordinated set of automatic protection actions, including load shedding and controlled system separation, designed to arrest cascading failures and preserve as much of the system as possible during severe disturbances.13) |
Resilience vs. reliability
Reliability concerns continuous electricity supply under normal operating conditions and foreseeable contingencies. Resilience concerns the system's response to high-impact, low-probability events and chronic stresses that exceed normal planning assumptions. A reliable system may lack resilience if it cannot cope with conditions it was not designed for.
Resilience vs. preparedness
Resilience describes the capacity to withstand, adapt to, and recover from disruptions. Preparedness describes the ability to anticipate risks and coordinate responses before disruptions materialise. A system can be resilient in its technical design while underprepared institutionally. The 2025 Iberian blackout illustrated this gap: renewable installations met technical performance standards individually, but the system lacked the grid-forming inverter deployment and cross-TSO coordination protocols that preparedness planning would have identified as necessary.